JPH06144657A - Paper feeder - Google Patents

Abstract

(57) [Summary] [Purpose] Correctly orient the paper and feed it. [Structure] The paper feed roller 21 is configured as a short roller that comes into contact with only the central portion of the recording paper S in the width direction, and the recording paper S is delivered obliquely by alternately driving the roller 21 and the paper feed roller 41. In case of
The leading edge a that first comes into contact with the stopped paper feed roller 41
The recording paper S is instantly swung by the paper feeding force acting on the central portion and the orientation is adjusted correctly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device, and more particularly to a sheet feeding device having a skew prevention function.

[0002]

2. Description of the Related Art In a paper feeding device for feeding stacked sheets of paper one by one to a printing section or the like, if the paper is misaligned in the width direction at the initial stage of paper feeding, the paper is obliquely fed. As a result, inconveniences such as wrinkling of the paper and paper jamming occur.

To address this problem, Japanese Patent Publication No. 58-66
In the device disclosed in Japanese Patent No. 33, a paper fed by a paper feed roller is shielded by a pair of paper feed rollers rotating in the opposite direction on the lower side of the paper feed direction, and the leading end of the paper is adjusted by a loop generated at that time. It was done like this. This one is
It's excellent in being able to correct the orientation of the paper,
On the other hand, some devices have a problem that a relatively long time is required for the skew prevention processing.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and its object is to:
Another object of the present invention is to provide a new sheet feeding device capable of shortening the time required for skew prevention.

[0005]

That is, according to the present invention, as a paper feeding device for achieving such a problem, a short roller in which a roller at the starting end side of a cut sheet is in contact only with a central portion in the width direction of the cut sheet. The roller is formed as a roller, and the switching means is provided in a part of the driving force transmission path connected to the single driving means to switch the roller on the starting end side and the roller located on the lower side in the paper feeding direction of the roller. It is designed to be driven.

[0006]

Embodiments Now, the embodiments shown in the drawings will be described. 1 and 2 show an embodiment of the present invention applied to a printer. The printer body indicated by reference numeral 1 in the drawing is configured to be capable of being placed horizontally and vertically, and FIG.
It is shown as a horizontal state with the bottom.

The printer main body 1 has a paper feed tray 10 in which the recording papers S as cut sheets are stacked.
And a paper feed roller unit 20 that feeds the recording paper S in the paper feed tray 10 at the central portion in the width direction and separates it from the paper feed roller 41 one by one, and the fed recording paper. A paper feed roller unit 40 including a paper feed roller 41 that is temporarily stopped at the time of feeding to adjust the direction of S
A paper discharge roller unit 50 that discharges the recording paper S, which has been recorded and written on the platen 4, onto the stacker 5 in cooperation with the paper feed roller unit 40, and the carriage 6.
A driving force transmission switching unit 70 that switches the driving force of the motor 71 to either the paper separating roller unit 10 or the paper feeding roller unit 40 by being operated by a part of 0 is provided.

The paper feed tray 10 is constructed such that the left side of the tray main body 11 is a fixed edge guide 12 and the right side is a movable edge guide 13 that slides according to the paper size, and is a one side reference (the left side of the drawing in this embodiment). And in addition,
A pad holder 14 for pressing the front end of the recording paper S against the peripheral surface of the paper feed roller 21 is attached to the front end of the tray body 11 while being biased upward by a spring 15.

The paper feed roller unit 20 is composed of a paper feed roller 21 that comes into contact with the central portion of the recording paper S in the width direction and feeds it out by a frictional force, and a drawing roller 22 arranged on the upper side in the paper feed direction. Therefore, these are formed to have a length of ten percent or more of the paper width, and the paper feed roller shaft 2 is provided so that they can contact the surface of the recording paper S equally.
It is assembled in a roller holder 23 which rotates about 5 as a fulcrum.

Reference numeral 30 denotes a roller gear that transmits a rotational driving force in the paper feed direction to the rollers 21 and 22. The roller gear 30 arranged in the roller holder 23 so as to face the paper feed roller 21 has a frictional force. It is connected to the paper feed roller shaft 25 via a torque limiter composed of a plate 28 and a spring 29 that presses the plate 28.

As shown in FIG. 3, the pinion 31, which is integral with the roller gear 30, has two planet gears 33, 33 on a planet lever 32 that idles on the feed roller shaft 25.
Are engaged with each other, and the planetary gear 33 is locked on the side of the paper feed roller 21 when the roller gear 30 rotates, and contacts the planetary lever 32 when the roller gear 30 stops to contact the planetary gear 3.
The rack 3 having the claw 34 for overrunning the sheet feeding device 3 and the projection 35 for pressing the planetary lever 32 is provided. ), As shown in FIG.
The planetary gear 33 is restrained by means of which the rotational driving force integrated with the roller gear 30 is transmitted to the paper feeding roller 21, and when the rotational driving force to the paper feeding roller 25 is cut off, the rack 3 operates the planetary lever 33. Press the planetary gear 33 to the pinion 33.
The paper feed roller 21 can be rotated independently in the paper feed direction by rotating the paper feed roller 21 above.

On the other hand, the roller gear 30 is movably coupled to a pull-out roller gear 38 integral with the pull-out roller 22 via an intermediate gear 37 rotatably supported in the elongated hole 24 of the roller holder 23. When the paper feed roller shaft 25 receives the rotational driving force, the intermediate gear 37
The rotation in the paper feed direction is transmitted to the pull-out roller 22 via
When the paper feed roller shaft 25 stops, the intermediate gear 3
7 and the drawing roller gear 38 are disengaged from each other to allow the drawing roller 22 to rotate independently in the paper feeding direction.

The paper feed roller unit 40 is composed of a paper feed roller 41 and a driven roller 45. The paper feed roller 41 is driven by a paper feed motor 71 via a driving force transmission switching unit 70 which will be described later. It is attached to the shaft 42.

A paper discharge roller unit 5 disposed on the lower side of the paper feed roller unit 40 with the platen 4 interposed therebetween.
0 is configured to rotate in conjunction with the paper feed roller 41 through an intermediate gear 51 that meshes with a pinion 44 that is integral with the paper feed gear 43, and a paper discharge gear 53 that meshes with the intermediate gear 51.
The attached shaft 52 is integrally formed of a resin material.

In order to eliminate processes such as deburring on the shaft 52, as shown in the cross section in FIG. 1, a paper discharge roller 54 having a cross-shaped cross section and a paper discharge having a three-pronged cross section. The rollers 55 are formed alternately, and each roller 54,
The ridge portion of 55 is configured to alternately contact the surface of the recording paper S. Therefore, the cross-sectional shape of these rollers may be formed in other shapes such as a quadrangle or a hexagonal shape, as long as they can be easily divided into molds and released from each other and have ridges that alternately contact the surface of the recording paper S.

On the other hand, the paper feed roller 21 and the paper feed roller 41
Drive force transmission switching unit 7 for switching and transmitting drive force to
0 is arranged at its home position so that the carriage 60 can be switched.

73 is a paper feed motor 71 attached here.
As shown in FIG. 4 (a), this gear 73 is constantly biased by a spring 75 and is always located leftward in the figure, and is a pinion integral with the gear 73. 74 is meshed with the first intermediate gear 76, and the rotational force is transmitted to the paper feed roller 41 via the paper feed gear 43 which meshes with the pinion 77 integral with the first intermediate gear 76, and FIG. As shown in, spring 75
When it is displaced to the right in the figure against the second intermediate gear 78
The rotational force is transmitted to the paper feed roller 21 via a pinion 79 that meshes with the internal gear 26 at the end of the paper feed roller shaft 25.

Reference numeral 80 denotes a cam member for displacing the switching gear 73 rightward in the figure against the spring 75. The cam member 80 is rotatably supported on the frame 9 about a shaft 82 as a fulcrum. The other end 81 projects into the moving area of the carriage 60 and abuts against a part of the carriage 60 that has moved to the home position to rotate, and the cam surface 83 of the other end 81 projects the tip of the pinion 74 that is integral with the switching gear 73. The surface 74a is pressed to displace the switching gear 73 to the right in the figure.

Reference numeral 6 in the drawing denotes a paper detection sensor for detecting the leading end of the recording paper S fed to the paper feed roller 21, and reference numeral 61 denotes, for example, a heat sensitive device mounted on the carriage 60. A recording head 62 of the type is a guide bar for guiding the carriage 60 in the longitudinal direction of the platen 4, respectively.

Next, the operation of the apparatus thus configured will be described. In the recording / writing standby state, the carriage 60 is located at the home position of the printer body 1 as shown in FIG. In this state, a part of the carriage 60 presses the other end 81 of the cam member 80 in the direction perpendicular to the paper surface, rotates the shaft 82 about the shaft 82, and puts the projecting end surface 74a of the pinion 74 on the top surface 85 thereof. In this way, the switching gear 73 is displaced to the right in FIG. 2, meshes with the second intermediate gear 78, and the paper feed motor 71 is engaged via the pinion 79 integral with the second intermediate gear 78 and the internal gear 26 meshing with the pinion 79. And the paper feed roller shaft 25 are connected.

When the paper feed command signal is output in this state, the started paper feed motor 71 causes the paper feed roller 21 and the pull-out roller 22 which are interlocked with each other via the intermediate gear 37.
Is rotated to feed the uppermost recording paper S placed on the paper feed tray 10 toward the paper feed roller unit 40.

By the way, as described above, since the rollers 21 and 22 are configured so as to come into contact with only the central portion of the recording sheet S in the width direction and to feed the recording sheet S, as shown in FIG. When the recording paper S is fed out in an inclined state for some reason, the recording paper S receiving the feeding force in the central portion in the paper width direction is centered on the left end portion a which first comes into contact with the paper feeding roller 41. Upon receiving a counterclockwise moment, it momentarily turns in the direction of the arrow X in the figure and stops with its leading edge correctly aligned with the axis of the paper feed roller 41.

On the other hand, together with this, the paper leading edge detecting sensor 6 arranged immediately before the paper feeding roller unit 40 detects the leading edge of the fed recording paper S and outputs a detection signal, and a sequence control circuit (not shown). The carriage motor is actuated via the arrow to start scanning the carriage 60 for recording and writing.

Then, as shown in FIG. 4A, when the carriage 60 starts to move to the right in the figure, it is displaced to the right in the figure by a part of the carriage 60 via the cam member 80. The switching gear 73 is released to the left in the figure by the urging force of the spring 75 at the same time when the pressing force of the carriage 60 is released, and the meshing with the second intermediate gear 78 is released, and the pinion 77 integral with this is first Intermediate gear 76
And the paper feed gear 43 that meshes with the pinion 77.
The paper feed roller 41 is rotated via the paper feed roller 41, and the recording paper S whose orientation is adjusted is delivered to the platen 4 together with the driven roller 42 which rotates in contact with the paper feed roller 41.

On the other hand, by this switching, the intermediate gear 51
The paper discharge roller shaft 52, which has started to rotate via the recording paper S, has completed the recording and writing while alternately contacting the respective edges of the paper discharge rollers 54 and 55 having different cross-sectional shapes with the recording paper S. Is discharged onto the stacker 5, and a series of paper feeding operation is completed.

Although the present invention has been described with reference to the embodiment applied to a printer, it goes without saying that the present invention can also be applied to a paper feeding device of a copying machine or a general printing device. Nor.

In the above embodiment, the skew is prevented between the paper feed roller 21 and the paper feed roller 41, but the same operation is performed between the paper feed roller 21 and the platen roller. It can also be configured to do so.

[0028]

As described above, according to the present invention, the roller on the starting end side of the cut-out sheet is constituted as a roller which is in contact only with the central portion in the width direction of the cut-out sheet, and this roller and the lower side in the paper-feeding direction. Since the rotational drive force is switched and transmitted to the roller located on the side, even if the cut sheet fed by the roller on the starting end side is skewed for some reason, the feeding force is applied to the central portion in the width direction. When this cut sheet comes into contact with the roller on the lower side in the stopped state, it will momentarily turn around the tip part that first abuts, and its leading edge will be equal to the lower roller. By making contact, the posture of the cut sheet can be quickly corrected.

Moreover, since the front and rear rollers are driven by switching one by one, the drive motor to be used can be further downsized and the power consumption can be further reduced especially in a small device. You can

[Brief description of drawings]

FIG. 1 is a plan view of an apparatus showing an embodiment of the present invention.

FIG. 2 is a side view showing the same device in section.

3A and 3B are diagrams showing respective operations of a rotation transmission mechanism provided in a paper feeding unit.

4A and 4B are diagrams showing respective operations of the rotation transmission switching unit.

5 (a) and 5 (b) are explanatory views showing respective states of sheet feeding by the same apparatus.

[Explanation of symbols]

 10 Paper Feed Tray 21 Paper Feed Roller 22 Draw Roller 25 Paper Feed Roller Shaft 30 Roller Gear 32 Planetary Lever 35 Rack 41 Paper Feed Roller 54, 55 Paper Discharge Roller 60 Carriage 70 Rotation Transmission Switching Unit 73 Switching Gear 80 Cam Member

Claims (1)

[Claims] 1. A roller on the delivery start end side of a cut sheet is formed as a short roller that contacts only the central portion in the width direction of the cut sheet, and is switched to a part of a driving force transmission path connected to a single driving means. A sheet feeding device, characterized in that means is provided to switch and drive the roller on the starting end side and the roller located on the lower side of the roller in the paper feeding direction.